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Open PhD project: Aluminium release and secondary hydroxide (trans-) from primary silicates in acidic soils

Position
Open PhD project: Aluminium release and secondary hydroxide (trans-) from primary silicates in acidic soils

Employer
Max Planck Institute for Biogeochemistry, Jena logo

Max Planck Institute for Biogeochemistry, Jena

The Max Planck Institute for Biogeochemistry is dedicated to the study of global cycles of essential elements on Earth, their interactions among the biosphere, atmosphere, geosphere and the oceans, and their interrelation with the physical climate system.

The institute was founded in 1997 by the Max Planck Society as the third Max Planck Institute in Jena. In 2003, the institute moved into its new building on the Beutenberg Campus. The Science Campus is home to several academic and for-profit research institutions and offers together with the Friedrich-Schiller University Jena excellent potential for local scientific collaborations.

Biogeochemical research is highly interdisciplinary and international. Scientists from all over the world are attracted to our institute and our research is often conducted in remote and exotic locations worldwide.

Homepage: http://www.imprs-gbgc.de


Location
Jena, Germany

Sector
Academic

Relevant divisions
Biogeosciences (BG)
Geochemistry, Mineralogy, Petrology & Volcanology (GMPV)
Soil System Sciences (SSS)

Type
Full time

Level
Student / Graduate / Internship

Salary
PhD researchers receive either a scholarship (1,200 EUR for 4 years) which is free of tax and social insurance or a support contract (about 1,600 EUR for 3 years).

Preferred education
Master

Application deadline
27 August 2019

Posted
5 July 2019

Job description

In cooperation with the Friedrich Schiller University Jena, the Max Planck Institute for Biogeochemistry houses a unique and flexible research program that grants German and foreign students a broad selection of learning opportunities while still maintaining a research focus.
The IMPRS-gBGC offers a PhD program specializing in global biogeochemistry and related Earth system sciences. The overall research and teaching focuses on:

  • Improved understanding of biogeochemical processes with an emphasis on terrestrial ecosystems
  • Development of observational techniques to monitor and assess biogeochemical feedbacks in the Earth system
  • Theory and model development for improving the representation of biogeochemical processes in comprehensive Earth system models

Project description:
In forest ecosystems under low to medium pH conditions, secondary hydrous Al-oxides like boehmite, gibbsite, diaspore, or nordstrandite and aqueous Al complexes are of paramount importance. These Al phases are involved in several environmentally relevant processes such as pH buffering at low pH, formation of organo-mineral mixed phases, soil-organic-matter dynamics, transformation of organic matter, as well as incorporation of inorganic contaminants. Another important aspect of Al speciation concerns the toxicity of Al to plants (catchword term “forest decline”). The formation and transformation of (hydrous) Al oxides is known to be favoured in acidic soils with coniferous vegetation. Yet, these environments also exhibit high amounts of mobile humified organic matter that may interact with the Al-phases to form organo-mineral colloidal phases that are involved Al-export and the processes of podsolization. Despite its importance in such environments, (hydrous) Al oxides have been rarely studied due to analytical difficulties: they are small and usually display poor crystallinity. Therefore, only a few Al phases have been doubtlessly identified in soil. A better understanding of their formation and subsequent ageing is thus mandatory to rate their role for major biogeochemical cycles of e.g. carbon and nitrogen. We intend to combine well defined incubation experiments with the investigation of natural hydrous Al-oxides sampled from acidic topsoil and subsoil horizons collected from Cambisols developed from siliciclastic rock at AquaDiva CZE (Würzbach, Thüringen, Germany) and Spodosols developed from Granites (Fichtelgebirge, Bavaria, Germany). The samples will be analysed with bulk and spatially resolved spectroscopic techniques. Laboratory weathering, transformation and release experiments with different Al-silicates as precursor minerals a will be run in the presence or absence of microbial consortia obtained from forest floor and soil extracts by incubation experiments. The newly formed Al phases will be studied by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance spectroscopy (Al-NMR), atomic force microscopy (AFM); electron micro probe analysis (EMPA), scanning and transmission electron microscopy (SEM/TEM), X ray diffractometry (XRD) and XAS (depending on successful beamtime acquisition). The lab synthesized phases will then be compared with hydrous Al phases and coatings formed in soil under natural conditions.

Possible Collaborations
Age of organic matter of mineral-organic mixed phases will be studied together with Sue Trumbore.
Possible Collaborations beyond AquaDiva/IMPRS/Jena Experiment:
Synchrotron based XAS-spectromicrosopy may be studied together with Jürgen Thieme (NLS2, Brookhaven, USA).


How to apply

Online applications for the program are open to well-motivated and highly-qualified candidates from all countries. A prerequisite is a diploma or master of science degree in geophysical sciences, environmental sciences, biological sciences, physics, chemistry, computer sciences or related fields, including a corresponding thesis. Proficiency in English is required since English is the official language of the program.

Requirements
Applications to the IMPRS-gBGC are open to well-motivated and highly-qualified students from all countries. Prerequisites for this PhD project are

  • a Master’s degree in Biogeoscience, Geoecology, Soil Mineralogy, Mineralogy, Soil Science, Environmental Geology, Clay mineralogy or related
  • Sound education in soil science or mineralogy with special emphasis in soil mineralogy
  • Knowledge in lab experimentation, spectroscopic and spectromicroscopic techniques or synchrotron based X-ray absorption spectroscopy is welcome
  • excellent oral and written communication skills in English

The Max Planck Society seeks to increase the number of women in those areas where they are underrepresented and therefore explicitly encourages women to apply. The Max Planck Society is committed to increasing the number of individuals with disabilities in its workforce and therefore encourages applications from such qualified individuals.